A154087 Number of planar triangular n X n X n nonnegative integer grids symmetric both under 120 degree rotation and reflection with every similarly oriented 5 X 5 X 5 subtriangle summing to 12.

22, 40, 80, 53, 27, 67, 30, 17, 28, 9, 10, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6, 9, 9, 9, 9, 6

Offset

5,1

Comments

Pattern 6 9 9 9 9 starts at n=16 and continues through at least n=51.

Links

Table of n, a(n) for n=5..51.

Example

Maximal zeros solution for n=16
.................6
................0.0
...............0.0.0
..............0.2.2.0
.............0.0.2.0.0
............4.1.0.0.1.4
...........0.1.0.2.0.1.0
..........0.0.0.2.2.0.0.0
.........0.2.2.0.0.0.2.2.0
........0.0.2.0.1.1.0.2.0.0
.......4.1.0.0.1.2.1.0.0.1.4
......0.1.0.2.0.1.1.0.2.0.1.0
.....0.0.0.2.2.0.0.0.2.2.0.0.0
....0.2.2.0.0.0.2.2.0.0.0.2.2.0
...0.0.2.0.1.1.0.2.0.1.1.0.2.0.0
..6.0.0.0.0.4.0.0.0.0.4.0.0.0.0.6

Crossrefs

Sequence in context: A188156 A026061 A138040 * A063327 A066957 A118602

Adjacent sequences: A154084 A154085 A154086 * A154088 A154089 A154090

Keyword

nonn

Author

R. H. Hardin Jan 04 2009

Status

approved